1. Field of the Invention
The present invention relates generally to a method for separating chips from a semiconductor wafer and more particularly, to a non-physical cutting method for separating a semiconductor wafer into individual chips.
2. Description of the Related Art
The conventional methods for separating a semiconductor wafer into chips extensively used nowadays are primarily physical cutting methods. Specifically speaking, the so-called “physical cutting methods” include, but not limited to, the sawing method of using a diamond saw blade and a laser cutting method. These methods can be seen in U.S. Pat. Nos. 6,121,118, 6,924,210 and 7,550,367. However, there are in fact more or less disadvantages in these physical cutting methods. For example, the cutting edge of the chips tends to be damaged in the sawing process and the chips may be contaminated by the cutting debris or powders. On the other hand, the separated cut chips may be contaminated by the ashes caused by the high-temperature laser cutting. In addition, the cutting rate of the aforesaid two methods is unsatisfied.